THE PLAYBOOK · 556856
Know the goal in Diagonal Sudoku
Read the aim of Diagonal Sudoku, then make your first move. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. Keep the game area visible while you use its controls. Treat the first round as a chance to learn the controls. Check the relevant rule before repeating a move.
Try a more deliberate round
After a move, check what changed. Decide which rule explains the new state before acting again. Notice the feedback after each input.
The purpose of your moves
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. Keep that objective in view throughout the round. Notice how the game responds to your input.
How a round unfolds
- Select an empty cell. The original clues cannot be edited.
- Choose a symbol from the number pad, or type it on a keyboard.
- Turn Notes on to record candidate symbols without committing an answer.
- Use Check entries to check your filled values. Hint reveals one value from the verified solution.
- Complete the board, or choose New puzzle for another board.
Using the playing area
Tap or click a cell and use the number pad. Keyboard: arrows select cells; digits (and A–G on 16×16) enter values; Backspace erases. Keep the playing area visible while using these controls. Read the example below alongside these instructions.
Follow the example
On one puzzle in this collection, row 1, column 1 has 1 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Use the example as a guide rather than a substitute for reading your board. Keep the controls nearby.
A useful caution
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Take a moment to reassess the position before continuing. Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart.
Further help with the game
When I return, what is the goal of Diagonal Sudoku?
Here is the relevant explanation: Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once.
Before I begin, how do I control Diagonal Sudoku?
Keep this in mind: Tap or click a cell and use the number pad. Keyboard: arrows select cells; digits (and A–G on 16×16) enter values; Backspace erases.
For this browser game, what example helps explain Diagonal Sudoku?
Keep this in mind: Before filling a cell, compare the symbols already used in its row, column and 3 × 3 region. A candidate must be absent from all three. The two long diagonals must also contain each symbol once.
For a quick reminder, what should I watch out for in Diagonal Sudoku?
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
Before I begin, what format does Diagonal Sudoku offer?
For clarity: Play using the solo mode shown on this page. Read the controls before starting a new round.
For this browser game, which play mode does Diagonal Sudoku use?
The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.